It is well known that patients who lie for long periods of time on a flat mattress develop bed sores where pressure points occur between bony structures and the mattress. To alleviate this condition without acquiring a great deal of nursing time for turning the patient manually, alternating pressure point mattresses are known wherein two sets of interdigitated cells are provided in the hollow mattress, alternating ones of which are inflated while those between are deflated and this cycle is regularly repeated between the two sets of cells so that alternately one set or the other is supporting the patient.
Prior art hollow mattresses of this type are usually manufactured by forming the interdigitated cells in a first step and then in a second step by hand sealing rigid air conduits in a side of the mattress. This manufacturing process can be inefficient because it requires hand manipulation of a rather large hollow mattress in order to hand seal the rigid air conduits. Apart from being cumbersome, the hand manipulation may damage a partially made mattress. Further, the rigid conduits tend to protrude from the sealed edge of the hollow mattress and may impede bed making or poke a user of the mattress.
End flaps, as disclosed in U.S. Pat. No. 3,199,124, are also known for holding the hollow mattress in position on a bed, usually on top of an ordinary mattress. The end flaps serve to tuck under the head and foot of the bed to retain the hollow mattress in place, for example, when the bed is gatched. The known end flaps are provided as separate pieces of material secured to a hollow mattress. The flaps are attached along an edge including alternating ones of chambers from the two different sets. A length of edges of the hallow mattress which include alternating ones of air chambers, substantially shrinks upon inflation, wrinkling and distorting the flaps attached to such edges. Wrinkled end flaps are disadvantageously difficult to tuck and do not sufficiently retain the hollow mattress in position on the bed, for example, when a patient moves into or out of bed.
The known method of manufacturing a hollow mattress with end flaps is to secure the end flaps to the mattress while forming the interdigitated cells. This manufacturing process is inefficient because of the added step of aligning the end flaps with the hollow mattress, and because the addition of end flaps increases the size of the mattress and makes hand manipulation of the mattress for hand sealing of prior art rigid conduits even more cumbersome and inefficient.
Corner tapes or straps, such as those disclosed in U.S. Pat. Nos. 3,467,081 and 4,454,615, are also known for holding an inflatable mattress in position on a bed. Such straps, however, are typically attached to the mattress in a more or less point contact and thus the entire securement load is borne by the points at which the straps are connected. This type of prior art mattress disadvantageously impairs bed making and bed changing, because the securement straps are somewhat difficult and cumbersome to secure about the corners of the mattress. The straps also tend to tear away from the air mattress, rendering them useless and possibly puncturing the mattress. Manufacture of this type of inflatable mattress is inefficient because it requires the additional step of die cutting the straps or attaching the corner tapes and reinforcing gussets.